1H-Pyrrole-2-carboxylic acid.

In the title compound, C(5)H(5)NO(2), the pyrrole ring and its carboxyl substituent are close to coplanar, with a dihedral angle of 11.7 (3)° between the planes. In the crystal structure, adjacent mol-ecules are linked by pairs of O-H⋯O hydrogen bonds to form inversion dimers. Additional N-H⋯O hydrogen bonds link these dimers into chains extending along the a axis.

Related literature

For pyrroles sourced from marine organisms, see: Faulkner (2002 ▶). For the bioactivity of pyrrole derivatives, see: Banwell et al. (2006 ▶); Sosa et al. (2002 ▶). For related structures, see: Zeng (2006 ▶); Zeng et al. (2007 ▶). For graph-set motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C5H5NO2

M = 111.10

Monoclinic,

a = 14.080 (3) Å

b = 5.0364 (10) Å

c = 14.613 (3) Å

β = 98.969 (3)°

V = 1023.6 (3) Å3

Z = 8

Mo Kα radiation

μ = 0.11 mm−1

T = 173 K

0.42 × 0.40 × 0.37 mm

Data collection

Bruker SMART 1K CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.954, T max = 0.959

2277 measured reflections

1006 independent reflections

875 reflections with I > 2σ(I)

R int = 0.015

Refinement

R[F 2 > 2σ(F 2)] = 0.063

wR(F 2) = 0.191

S = 1.06

1006 reflections

74 parameters

H-atom parameters constrained

Δρmax = 0.74 e Å−3

Δρmin = −0.73 e Å−3

Data collection: SMART (Bruker,1999 ▶); cell refinement: SAINT-Plus (Bruker, 1999 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809014044/sj2604sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809014044/sj2604Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C5H5NO2	F(000) = 464
Mr = 111.10	Dx = 1.442 Mg m−3
Monoclinic, C2/c	Melting point: 480 K
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 14.080 (3) Å	Cell parameters from 1751 reflections
b = 5.0364 (10) Å	θ = 2.8–27.0°
c = 14.613 (3) Å	µ = 0.11 mm−1
β = 98.969 (3)°	T = 173 K
V = 1023.6 (3) Å3	Block, colorless
Z = 8	0.42 × 0.40 × 0.37 mm

Bruker SMART 1K CCD area-detector diffractometer	1006 independent reflections
Radiation source: fine-focus sealed tube	875 reflections with I > 2σ(I)
graphite	Rint = 0.015
φ and ω scans	θmax = 26.0°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −17→13
Tmin = 0.954, Tmax = 0.959	k = −6→6
2277 measured reflections	l = −14→18

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.063	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.191	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.1108P)2 + 3.3345P] where P = (Fo2 + 2Fc2)/3
1006 reflections	(Δ/σ)max = 0.001
74 parameters	Δρmax = 0.74 e Å−3
0 restraints	Δρmin = −0.73 e Å−3

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

	x	y	z	Uiso*/Ueq
O1	0.12435 (12)	1.1503 (3)	0.53422 (12)	0.0223 (5)
C4	0.23786 (16)	0.8483 (5)	0.61313 (15)	0.0176 (6)
O2	0.07382 (14)	0.7350 (4)	0.56343 (15)	0.0373 (6)
H2A	0.0220	0.7923	0.5336	0.056*
N1	0.31542 (14)	1.0100 (4)	0.61094 (15)	0.0216 (6)
H1A	0.3144	1.1614	0.5808	0.026*
C3	0.26837 (17)	0.6325 (5)	0.66849 (17)	0.0208 (6)
H3	0.2299	0.4879	0.6828	0.025*
C5	0.14189 (16)	0.9228 (5)	0.56657 (15)	0.0173 (6)
C2	0.36767 (18)	0.6681 (5)	0.69974 (17)	0.0245 (6)
H2	0.4085	0.5521	0.7393	0.029*
C1	0.39405 (17)	0.9010 (6)	0.66242 (18)	0.0251 (6)
H1	0.4570	0.9740	0.6712	0.030*

	U11	U22	U33	U12	U13	U23
O1	0.0198 (9)	0.0190 (10)	0.0273 (10)	−0.0004 (7)	0.0008 (7)	0.0048 (7)
C4	0.0184 (12)	0.0182 (12)	0.0167 (11)	−0.0004 (9)	0.0039 (9)	−0.0005 (9)
O2	0.0298 (11)	0.0331 (12)	0.0472 (13)	−0.0029 (9)	0.0002 (10)	0.0044 (10)
N1	0.0191 (10)	0.0196 (11)	0.0253 (11)	−0.0027 (8)	0.0013 (8)	0.0062 (8)
C3	0.0210 (12)	0.0198 (12)	0.0216 (12)	0.0003 (9)	0.0035 (9)	0.0020 (9)
C5	0.0192 (12)	0.0164 (11)	0.0167 (11)	−0.0002 (9)	0.0042 (9)	−0.0008 (9)
C2	0.0220 (13)	0.0291 (14)	0.0215 (12)	0.0052 (10)	0.0009 (9)	0.0038 (10)
C1	0.0174 (12)	0.0318 (14)	0.0256 (13)	−0.0013 (10)	0.0019 (9)	0.0030 (11)

O1—C5	1.250 (3)	N1—H1A	0.8800
C4—N1	1.367 (3)	C3—C2	1.413 (3)
C4—C3	1.383 (3)	C3—H3	0.9500
C4—C5	1.464 (3)	C2—C1	1.369 (4)
O2—C5	1.342 (3)	C2—H2	0.9500
O2—H2A	0.8400	C1—H1	0.9500
N1—C1	1.354 (3)
N1—C4—C3	107.8 (2)	O1—C5—O2	122.4 (2)
N1—C4—C5	121.3 (2)	O1—C5—C4	121.6 (2)
C3—C4—C5	130.8 (2)	O2—C5—C4	116.0 (2)
C5—O2—H2A	109.5	C1—C2—C3	107.2 (2)
C1—N1—C4	109.4 (2)	C1—C2—H2	126.4
C1—N1—H1A	125.3	C3—C2—H2	126.4
C4—N1—H1A	125.3	N1—C1—C2	108.6 (2)
C4—C3—C2	106.9 (2)	N1—C1—H1	125.7
C4—C3—H3	126.5	C2—C1—H1	125.7
C2—C3—H3	126.5
C3—C4—N1—C1	0.7 (3)	N1—C4—C5—O2	171.9 (2)
C5—C4—N1—C1	177.3 (2)	C3—C4—C5—O2	−12.3 (4)
N1—C4—C3—C2	−0.2 (3)	C4—C3—C2—C1	−0.3 (3)
C5—C4—C3—C2	−176.4 (2)	C4—N1—C1—C2	−0.9 (3)
N1—C4—C5—O1	−10.0 (3)	C3—C2—C1—N1	0.7 (3)
C3—C4—C5—O1	165.7 (2)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1i	0.88	2.22	2.951 (3)	141
O2—H2A···O1ii	0.84	2.16	2.986 (3)	166

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O1i	0.88	2.22	2.951 (3)	141
O2—H2A⋯O1ii	0.84	2.16	2.986 (3)	166

Symmetry codes: (i) ; (ii) .